The present invention relates to thermo-shrinking film labeling machines, and more specifically to a thermo-shrinking film cutting mechanism for a labeling machine.
In regular thermo-shrinking film labeling machines, a single or multiple rotary cutter means are used to cut the thermo-shrinking film. FIG. 1 shows the arrangement of the rotary cutter means in a thermo-shrinking film labeling machine according to the prior art. As illustrated, a plurality of rotary cutter holders C2 are equiangularly arranged around a center guide shaft C1, each cutter holder C2 holding a cutter blade C3, which is aimed at an annular groove C4 around the periphery of the center guide shaft C1, a motor C5 is driven to turn the cutter holders C2 through toothed transmission belts C6;C7. The cutter holders C2 each have a gear meshed with the toothed transmission belt C7. When the motor C5 is started, the cutter holders C2 are synchronously rotated to move the respective cutter blades C3 over the annular groove C4 on the center guide shaft C1, so as to cut off the thermo-shrinking film. When finishing one cutting operation, the cutter holders C2 must be synchronously rotated through 360.degree. and then set in position. However, because the cutter holders C2 are driven to rotate by the toothed transmission belt C7, vibrations occur when the toothed transmission belt C7 start to wear. Because the toothed transmission belt C7 wears quickly with use, a compensating measure must be taken. In order to eliminate this problem, an idle wheel C8 is installed and peripherally pressed against the toothed transmission belt C7 to keep the toothed transmission belt C7 in positive engagement with the gears of the cutter holders C2. Furthermore, because the cutter holders C2 are linked to one another through the toothed transmission belt C7, they are rotated synchronously when one cutter holder C2 is moved. Therefore, the user's hands tend to be injured by the cutter blade C3 of an adjacent cutter holder C2 when adjusting the position of the cutter blade C3 of a particular cutter holder C2.